Study: San Francisco Bay sea-level protections will cost $110B

Protecting the homes and businesses, highways and airports, sewage treatment plants and other key parts of society that ring San Francisco Bay’s shoreline from sea-level rise will be a massive challenge over the next generation. And it’s not going to come cheap, according to a new report.

The cost estimate: $110 billion by 2050, according to the study from the Metropolitan Transportation Commission, the Association of Bay Area Governments and the San Francisco Bay Conservation and Development Commission.

So far, only $5 billion of that money is in hand, the study said. The projects needed include expanding thousands of acres of wetlands, building dozens if not hundreds of miles of higher levees, constructing new tidal gates, strengthening sea walls, and raising roads in some areas around the nine-county Bay Area’s roughly 400-mile-long waterfront.

If nothing is done, $236 billion in property is at risk, the study says.

“It’s going to cost an awful lot of money to make sure the Bay Area is resilient along the shoreline,” said Larry Goldzband, executive director of the San Francisco Bay Conservation and Development Commission, a state agency. “That’s the bad news. If we don’t spend that money, it’s going to be a whole lot worse.”

More than 75,000 households and 200,000 jobs — including industries in Benicia, small businesses along the Marin County shoreline, the tourism economy of San Francisco’s Embarcadero and massive high-tech campuses lining the San Mateo-Santa Clara County waterfront — are estimated to be directly at risk by 2050, according to the study.

Global temperatures have risen 2.1 degrees Fahrenheit since 1880, mostly due to the burning of fossil fuels, which traps heat in the atmosphere.

The 10 hottest years since 1850 on Earth, when consistent modern temperature records began, have all occurred since 2010, according to NOAA, the National Oceanic and Atmospheric Administration, which is the parent agency of the National Weather Service.

The steadily warming climate has caused ocean levels to rise across the world in recent decades as glaciers and polar ice sheets have melted and warming sea water has expanded. San Francisco Bay has risen 8 inches since the mid-1800s.

During heavy winter storms on a high tide, the bay’s surface can rise another foot.

And more sea rise is on the way.

Recent studies by the U.S. Geological Survey and other scientific organizations estimate that, depending on the amounts of greenhouse gases released into the atmosphere in the coming years, the Pacific Ocean on the West Coast and San Francisco Bay will rise another 1 to 2 feet by 2050 and 4 feet or more by 2100.

In some areas, big projects are already are underway. San Francisco International Airport officials are moving ahead with a $587 million plan to build a 10-mile-long sea wall around the airport to stop runways from flooding during storms.

San Francisco has begun work on a $5 billion plan to rebuild the sea wall along the Embarcadero. Voters in Foster City approved a $90 million property tax hike in 2018 to raise their levee to hold back the rising bay.

From San Jose to Newark to Napa, scientists have been restoring thousands of acres old industrial salt evaporation ponds back to tidal marshes to absorb rising storm surges and waves.

The report says that a combination of state, federal and local funding will be essential to do more. But it notes that better coordination is needed among local governments to prioritize projects, particularly in areas that are low-income and at high risk of flooding, such as East Palo Alto, Alviso in North San Jose, and San Rafael’s Canal District.

“San Francisco Bay Area is ground zero for sea level rise,” said Warner Chabot, executive director of the San Francisco Estuary Institute, a nonprofit research organization based in Richmond. “This is a significant challenge. How do you get nine counties and 100 cities to figure out how to raise $100 billion to protect shoreline communities?”

The report says that Marin, Alameda, San Francisco and San Mateo counties have the highest overall financial risk. The study estimated the costs of protecting property from 17 inches of sea level rise by 2050, with a 100-year storm that would add another 3.5 feet of high tides and surges on top of that.

In many ways, the Bay Area already is ahead of other parts of the country, from Miami Beach, where huge hotels sit on sand just a few feet above sea level, to New Orleans, to New York City, where water poured into the subway system during Hurricane Sandy in 2012 and Hurricane Ida in 2021.

In 2016, voters in the nine Bay Area counties approved Measure AA, a $12 annual parcel tax, to fund wetlands restoration and flood control projects around the bay’s shoreline. The measure, which will raise $25 million a year for 20 years, already has funded dozens of wetlands restoration projects.

Last month, President Biden visited the Baylands nature preserve on the Palo Alto waterfront to announce a $575 million national NOAA grant program to help coastal communities nationwide confront rising seas.

“When I think of climate, I think of jobs,” he said. “When I think of climate, I think of innovation. When I think of climate, I think of turning peril into progress.”

David Lewis, executive director of Save the Bay, an environmental group in Oakland, said major projects such as raising Highway 37 in the North Bay, restoring another 40,000 acres of wetlands, and protecting wastewater treatment plants that serve millions of people cannot be avoided. The region will need significant federal, state and regional funding, he said.

“Whatever the cost is, it gets higher the longer we wait,” he said. “The most important message is to get started sooner.”